Pulmonary vein activation in atrial fibrillation and sinus rhythm.

AIMS: The purpose of this study was to determine the relationship between pulmonary vein (PV) electrical activation during atrial fibrillation (AF) and after cardioversion into sinus rhythm. METHODS AND RESULTS: Electrograms were recorded using a circular mapping catheter during AF and after cardioversion in 53 PVs from 41 patients. Two activation patterns were observed in AF. Group 1 had fixed, consistent, uniform activation sequences most (>70%) of the recording time. Group 2 had no fixed activation sequence. In Group 1, a constant single activation sequence pattern was seen in 22 PVs (Group 1a). The earliest PV activation sites were the same during AF and after cardioversion to sinus rhythm in 17 (77%) PVs from Group 1a. Fourteen of these 17 (82%) cases also had a common site of electrogram polarity reversal. In Group 2, a relationship between PV activation before and after cardioversion was not found. Segmental radio frequency (RF) ablation was performed during sinus rhythm after cardioversion. There was no difference in the number of atriovenous breakthroughs between the two groups (1.9+/-0.7 vs. 2.0+/-0.6 breakthroughs, P=NS). PV disconnection was achieved in all PVs with a mean RF duration of 13.5+/-4.5 min per vein in Group 1 and 14.0+/-4.9 min per vein in Group 2 (P=NS). CONCLUSION: A uniform PV electrogram pattern recorded during AF usually predicts the activation sequence and/or the polarity reversal sites during sinus rhythm. This pattern does not necessarily suggest a single atriovenous breakthrough point.     

Different strategies for performing pulmonary vein isolation in patients with pulmonary vein rhythm

Pulmonary vein (PV) isolation was performed in atrial fibrillation (AF) patients whose cardiac rhythm was dominated by the ectopic beats originating from the PV. We herein report two cases with dominant PV ectopic rhythm that underwent catheter ablation for the treatment of paroxysmal AF. In one case, a permanent pacemaker implantation was required to treat a symptomatic long sinus pause after the isolation of all four PVs, while no AF was documented during the 5-year period after ablation. However, the isolation of all four PVs except for a PV with a dominant ectopic rhythm was performed in the other case. The latter case was free from both AF and symptomatic bradycardia following the procedure without the implantation of a pacemaker. Selective PV isolation therefore appears to be an effective therapy to both achieve the successful treatment of AF and to prevent the manifestation of sick sinus syndrome.     

Electrophysiologically guided pulmonary vein isolation during sustained atrial fibrillation

INTRODUCTION: Sustained atrial fibrillation (AF) is frequently encountered during pulmonary vein (PV) isolation. The aim of this study was to evaluate the feasibility and safety of PV isolation during sustained AF. METHODS AND RESULTS: Thirty-seven patients (30 men, age 54 +/- 10 years) underwent Lasso-guided isolation of 87 PVs during sustained AF. Baseline PV electrogram patterns were classified into one of two types: organized, with consistent PV activation sequence; or disorganized, with constant variation of PV activation sequence. In disorganized activity, radiofrequency ablation was performed circumferentially around the Lasso while the earliest PV potential was targeted during organized activity. Complete left atrial (LA) to PV block during AF was identified by abolition or dissociation of all sharp potentials recorded within the vein. PV isolation then was verified during sinus rhythm. Baseline activation patterns of PV potential were organized in 32 PVs (37%) [more frequently in inferior veins than superior veins (53% vs 26%, P = 0.01)] and disorganized in 55 PVs (63%). In 59 of 87 PVs, isolation was begun and completed during AF. Radiofrequency ablation organized PV activation sequence in 75% prior to isolation. LA-PV block was confirmed during sinus rhythm in 54 (92%) of 59 PVs. In 28 of 87 PVs, sinus rhythm was restored before complete LA-PV block. Complete isolation was achieved in all 87 PVs without complications. CONCLUSION: PV isolation can be effectively and safely performed during sustained AF, preceded in most cases by organization of PV electrogram activity. This strategy may be the preferred alternative to multiple intraprocedural cardioversions.     

Catheter ablation of chronic atrial fibrillation targeting the reinitiating triggers

Trigger Ablation in Chronic AF. Introduction : We assessed the mode of reinitiation of atrial fibrillation (AF) after cardioversion and the efficacy of ablating these foci of reinitiation in patients with chronic AF.
Methods and Results : Fifteen patients, 7 with structural heart disease, underwent mapping and catheter ablation of drug-resistant AF documented to he persistent for 5 ± 4 months. In all patients, cardioversion was followed by documentation of P on T atrial ectopy and early recurrence, which allowed mapping of the reinitiating trigger or the source of ectopy. Radiofrequency (RF) ablation was performed at pulmonary vein (PV) ostia using a target temperature of 50°C and a power limit of 30 to 40 W, with the endpoint being interruption of all local muscle conduction. A total of 32 arrhythmogenic PVs and 2 atrial foci (left septum and left appendage) were identified: 1, 2, and 3 or 4 PVs in 5, 3, and 6 patients. RF applications at the ostial perimeter resulted in progressively increasing delay, followed by abolition of PV potentials in 8, but potentials persisted in 6. A single ablation session was performed in 7 patients and 8 underwent two or three sessions because of recurrence of AF; ablation was directed at the same source due to recovery of local PV potential or at a different PV. No PV stenosis was noted either acutely or at repeated follow-up angiograms. Nine patients (60%) were in stable sinus rhythm without antiarrhythmic drugs at follow-up of 11 ± 8 months. Anticoagulants were interrupted in 7 patients.
Conclusion : PVs are the dominant triggers reinitiating chronic AF in this patient population. Elimination of PV potentials by ostial RF applications results in stable sinus rhythm in 60%. A larger group and longer follow-up are needed to investigate further the role of trigger ablation in curative therapy for chronic AF.     

心房颤动导管消融复发患者二次消融研究

目的心房颤动（房颤）导管消融治疗仍然存在一定的复发率,而其复发的特点目前仍然不清,本文对房颤消融复发患者二次消融的特点进行分析。方法共442例房颤消融治疗患者中,29例消融后复发的患者[男性19例,年龄（56±11）岁],本文患者复发时间〉6个月。对这些复发患者进行二次导管消融治疗。分析和对比初次与二次消融的电生理特点。结果29例房颤患者（20例为阵发性房颤,9例为持续性房颤）复发时间6—33（11．3±5．3）个月,所有患者初次消融后均服用3个月抗心律失常药。在复发的29例患者中,（1）3例初次消融术采用单纯靶肺静脉电隔离,二次消融发现1例出现非消融肺静脉触发灶,予以补充消融;另2例发现原靶肺静脉均有传导恢复,予以所有肺静脉经验性电隔离。（2）12例初次消融策略为所有肺静脉（48根）经验性电隔离,二次消融时发现所有患者存在不同程度的肺静脉传导恢复（36根）,8例再次所有肺静脉节段电隔离（其中1例发现上腔静脉起源予以针对性电隔离）;4例患者采用三维标测系统指导下同侧肺静脉环形电隔离。（3）12例患者初次消融策略为三维标测系统指导下同侧肺静脉环形电隔离,二次消融时重复进行环肺静脉电隔离。1例患者术中发现左心房局灶性房性心动过速（房速）并成功消融,2例患者术中出现左心房不典型心房扑动（房扑）成功消融。二次消融术后随访（15±10）个月,5例患者出现房颤复发（阵发性房颤1例,持续性房颤4例;成功率82．8％）,1例患者出现严重左肺静脉狭窄。结论对于房颤进行肺静脉消融电隔离治疗,其复发患者以肺静脉传导恢复为复发的主要原因。单纯进行靶肺静脉消融的部分患者,其他肺静脉的触发灶对于复发起着重要的作用。部分复发患者与非肺静脉起源的触发灶相关。复发的房颤患者,再次导管消融治疗可以达到较高的治疗成功率。     

在心房颤动持续过程中行肺静脉电学隔离术的可行性

探讨在心房颤动 (简称房颤 )持续过程中行肺静脉电学隔离术的可行性。 9例在导管消融术中房颤持续发作的房颤患者 ,根据肺静脉环状标测电极导管记录的肺静脉激动特征采用 2种方法进行肺静脉开口部的消融 :①肺静脉激动有序且有一种或多种固定的激动顺序 ,采用射频导管消融环状电极记录的最早的激动部位 ;②肺静脉激动无序或无明确的激动顺序 ,首先使用超声球囊导管消融 ,如未达终点再加用射频导管消融。 2种方法的消融终点均为肺静脉电学隔离。总计对 31根肺静脉进行了消融 ,其中 2 8根在房颤心律下消融。房颤心律下电隔离肺静脉的成功率为 92 .9% (2 6根 )。总操作时间和X线透视时间分别为 1 38± 2 1min和 38± 9min。本组无肺静脉狭窄及其他并发症。随访 6 .3± 2 .9(3～ 1 1 )个月后 ,4例 (44.4% )患者无房颤发作 (无需药物 )。结论 :在房颤持续过程中行肺静脉电学隔离术方法可行 ,且较为安全 ;联用超声球囊消融和射频消融对于房颤发作过程中无序或无明确激动顺序的肺静脉具有较好的电学隔离效果。     

New approach to pulmonary vein isolation for atrial fibrillation using a multielectrode basket catheter.

BACKGROUND: Pulmonary vein (PV) isolation using a circular catheter creates an entrance block from the left atrium (LA) to the PV, which eliminates paroxysmal atrial fibrillation (PAF). A new approach to PV isolation during distal PV pacing is to use a basket catheter. METHODS AND RESULTS: Fifty consecutive patients with PAF underwent basket-catheter-guided PV isolation. PV pacing was performed from the distal electrode pair of the basket catheter. The exit breakthrough point was targeted for segmental PV isolation. The endpoint was the elimination of bidirectional PV - LA conduction. A repeat ablation procedure was performed in 12 of 14 patients who had recurrence of AF. The recovery of PV -LA conduction was noted in 24 of the 48 PVs, and 5 PVs (21%) had unidirectional block. At 12 months, 80% of patients were free of AF without antiarrhythmic drugs. No PV stenosis >50% was detected at 12 months after the procedure. CONCLUSIONS: This new approach for PV isolation during distal PV pacing using a basket catheter is useful for confirming bidirectional PV - LA conduction block. PV isolation that creates not only an entrance block but also an exit block at the PV - LA junction may be required to cure paroxysmal AF.     

Early Detection of Pulmonary Vein Reconnection After Isolation in Patients With Paroxysmal Atrial Fibrillation: A Comparison of ATP‐Induction and Reassessment at 30 Minutes Postisolation

Introduction: Catheter ablation for paroxysmal AF (PAF) is limited by an unacceptable recurrence rate, mainly due to pulmonary vein (PV) reconnection. Strategies to minimize reconnection include adenosine infusion and also a waiting period of 30 minutes after PV isolation. The aim of the present study was to assess whether these two strategies revealed the same conduction gap. Methods and Results: In total, 88 consecutive patients (54 males, mean age of 60 years) with drug refractory PAF underwent circumferential PV isolation (CPVI). After isolation of ipsilateral PVs, with entry and exit block checked using a circular mapping catheter, 20 mg ATP was injected during isoproterenol infusion to reveal dormant conduction gap(s). Unless the reconnection revealed by ATP persisted, PVs were further remapped with the circular mapping catheter at 30 minutes postisolation. Totally, PV reconnection was observed in 56 (64%) patients. 24.3% veins (80/329) were found reconnected. Reassessment at 30 minutes postablation was more efficient as compared to ATP induction (19.8% vs 14.6% for ATP). The agreement between these 2 methods is moderate (kappa value = 0.50). In veins that transiently reconnected after ATP administration and later observed at 30 minutes postablation, 94% (17 of 19) of them were found being reconnected with the same gap. Conclusion: Acute PV reconnection is common, occurring in 64% of patients, as detected by adenosine infusion and waiting time. Each shows a unique quality as compared to one another. The combined use of these 2 methods may reduce the AF recurrence rate after CPVI.     

Single procedure efficacy of isolating all versus arrhythmogenic pulmonary veins on long-term control of atrial fibrillation: a prospective randomized study.

BACKGROUND: Current atrial fibrillation (AF) ablation involves isolation of all pulmonary veins (PVs) with or without additional linear lesions. However, whether such extensive ablation is necessary is unclear. OBJECTIVE: The purpose of this study was to assess the efficacy of different ablation strategies on long-term AF control. METHODS: We prospectively randomized patients to undergo isolation of all versus arrhythmogenic PVs (identified by standardized stimulation protocol). PV isolation was guided by circular mapping catheter. The endpoint was entry/exit block persisting for > or = 20 minutes. Patients were evaluated at three clinic visits (at 6 weeks, 6 months, and 1 year) and multiple transtelephonic monitoring periods. Antiarrhythmic drugs were discontinued at 6 weeks. Primary study endpoint was long-term AF control (freedom or >90% reduction in AF burden off or on previously ineffective antiarrhythmic drugs at 1 year after a single ablation procedure). RESULTS: Over a 20-month period, 105 patients (76 men and 29 women, age 57 +/- 9 years; paroxysmal AF = 77) were randomized, and 103 patients completed 1-year follow-up (51 patients in all-PV arm, 52 patients in arrhythmogenic PV arm). The primary endpoint was achieved in 75 (73%) patients and was similar in patients randomized to all-PV arm versus arrhythmogenic PV arm [38 (75%) patients vs 37 (71%) patients, respectively; odds ratio 1.18, 95% confidence interval 0.50, 2.83, P = .70]. Secondary study endpoints, including freedom from AF off antiarrhythmic drugs, total procedure/fluoroscopy times, and occurrence of serious adverse events, were not different between the two groups. CONCLUSION: In a randomized comparison, isolation of arrhythmogenic veins was as efficacious as empiric isolation of all veins in achieving long-term AF control.     

Circumferential mapping and electric isolation of pulmonary veins in patients with atrial fibrillation

Information about the clinical efficacy and complications of the circumferential mapping and isolation of the pulmonary veins (PVs) in patients with atrial fibrillation (AF) is still limited. The present study included 75 patients (mean age 58 +/- 11 years, 20 women) with paroxysmal (n = 69) or persistent AF (n = 6). Mapping of PVs was performed with a circumferential mapping catheter. After preferential PV-left atrium (LA) electric inputs were defined, radiofrequency ablation was performed until complete isolation of the PVs from the LA was achieved. A total of 226 PVs were mapped; 195 (86%) showed typical PV potentials. Complete isolation of PVs from the LA was achieved in 173 PVs (89%). Detailed follow-up, including 7-day Holter monitoring at 1, 4, 9, and 12 months after intervention was performed. If AF reoccurred, PVs were mapped and reisolated. After a mean follow-up period of 230 +/- 133 days, 38 of 75 patients (51%) were in sinus rhythm. At 1, 4, and 9 months of follow-up, 31 of 65 patients (48%), 36 of 53 patients (68%, p = 0.04 as compared with the first month), and 21 of 28 patients (75%, p = 0.025 as compared with the first month), respectively, were in sinus rhythm. During follow-up, 30 patients (40%) underwent a second ablation procedure due to recurrence. Recurrences were related to resumption of PV muscle-left atrial conduction (27 patients) and/or extra PV foci (12 patients) or nonablated PVs (8 patients). Complications occurred in 17 patients (22%). PV stenosis was detected in 13 patients (25% to 50% in 7 patients and >50% in 6 patients). Pericardial effusion occurred in 4 patients. It was concluded that isolation of the PV from the LA is moderately effective in the prevention of AF recurrence and could be associated with serious acute and long-term complications.     

Mechanisms of recurrent atrial fibrillation after pulmonary vein isolation by segmental ostial ablation

OBJECTIVES: The aim of this study was to determine the mechanisms responsible for recurrent atrial fibrillation (AF) after pulmonary vein isolation (PV) by segmental ostial ablation. BACKGROUND: Recovery of conduction into a previously isolated PV is a common observation when there is recurrent AF soon after segmental ostial ablation. However, the mechanisms of recurrent AF have been unclear. METHODS: A repeat ablation procedure was performed in 50 patients who had recurrent paroxysmal AF at a mean of 7 +/- 6 months after segmental ostial ablation to isolate the PVs. During the repeat procedure, a ring catheter was inserted into each PV during sinus rhythm and AF to determine whether the veins were still isolated and, if not, whether there were PV tachycardias with a cycle length shorter than in the adjacent left atrium during AF. RESULTS: There was recovery of conduction over a previously ablated muscle fascicle in >/=1 PV in 49 patients (98%). There were 10 +/- 2 episodes of PV tachycardia per minute in 36 (72%) of the 50 patients during AF. Repeat ablation was performed by segmental ostial ablation (23 patients) or by left atrial catheter ablation to encircle the left- and right-sided PVs 1 to 2 cm from the ostia, with additional ablation lines in the posterior left atrium and mitral isthmus (27 patients). At 6-month follow-up, among 23 patients who underwent repeat ablation by segmental ostial ablation, AF recurred in 4 (21%) of the 19 patients who had PV tachycardias and in 3 (75%) of the 4 patients who did not (P = .03). Among the 27 patients who underwent left atrial ablation, AF recurred in 2 (12%) of the 17 patients who had PV tachycardias and in 1 (10%) of the 10 patients who did not (P = 0.7). CONCLUSIONS: Recovery of conduction in previously ablated muscle fascicles is a common finding in patients with recurrent AF after segmental ostial ablation. The efficacy of repeat segmental ostial ablation depends on the presence of PV tachycardias, whereas left atrial ablation is effective regardless of whether PV tachycardias are present or not during AF.     

Incidence and location of focal atrial fibrillation triggers in patients undergoing repeat pulmonary vein isolation: implications for ablation strategies

INTRODUCTION: The etiology of atrial fibrillation (AF) recurrences after pulmonary vein (PV) isolation is not well described. The aim of this study was to examine the reason for recurrent AF in patients undergoing a repeat attempt at AF trigger ablation. METHODS AND RESULTS: Patients with recurrent AF more than 1 month after ablation returned for repeat mapping and ablation. A circular mapping catheter was advanced to each previously targeted PV ostium to determine if the PV was still electrically isolated. Ectopy then was provoked with isoproterenol (up to 20 microg/min), burst pacing, and pacing into AF followed by cardioversion. The location of ectopy triggering atrial premature depolarizations (APDs) or AF was noted. Of 226 patients who underwent ablation of AF triggers, 34 (8 women and 26 men; age 56 +/- 10 years) with recurrent AF returned for a repeat procedure 207 +/- 183 days after the first procedure. There were 84 previously completely isolated PVs in these 34 patients. Thirty-three (39%) of 84 previously isolated PVs were still completely isolated at the time of the second procedure. Fifty-one PVs (61%) had evidence of recovered PV potentials. Fifty triggers of APDs and AF (n = 30) or APDs only (n = 20) were identified in these 34 patients. The majority of triggers [27/50 (54%)] originated from previously targeted PVs. Sixteen triggers [16/50 (32%)] originated from previously nontargeted PVs. CONCLUSION: The majority of AF recurrences originate from previously isolated PVs. One third of recurrent triggers originated from PVs that were not targeted during the initial ablation session. Although empiric isolation of all PVs may reduce recurrences, strategies to ensure ostial PV isolation and to prevent recurrent PV conduction after ablation should have the greatest impact on reducing AF recurrence.     

Efficacy of repeat pulmonary vein isolation procedures in patients with recurrent atrial fibrillation

INTRODUCTION: Pulmonary vein (PV) isolation is effective in the treatment of most patients with atrial fibrillation (AF). Some advocate the addition of linear ablation techniques to improve efficacy; however, previous studies suggest recurrent PV conduction is responsible for AF recurrence. The aim of this study was to determine the effectiveness of repeat PV isolation in patients with recurrent AF after an initial ablation procedure and to determine if any patient characteristics predict failure of repeat PV isolation procedures. METHODS AND RESULTS: Seventy-four patients with two or more AF ablation procedures using selective PV isolation were included. PV isolation was guided with multielectrode ring catheter recordings, electroanatomic mapping, and intracardiac electrocardiography. Radiofrequency energy was delivered using a 4-mm-tip catheter (maximum 40 W, 52 degrees C); cooled-tip ablation was performed in 10 patients. Linear ablation was not performed. Antiarrhythmic drugs were continued for at least 6 weeks after ablation; AF episodes during this period were censored. Reconnection of one or more segments of previously ablated PVs was observed in 97% of patients; reconnected PVs served as the trigger for AF in 77%. Repeat PV isolation resulted in AF control (cure or 90% reduction in AF episodes) in 64 patients (86%) over a follow-up period of 9.1 +/- 6.7 months. "High-risk" characteristics such as left atrial enlargement, persistent AF, or mitral regurgitation did not predict failure of repeat PV isolation procedures. CONCLUSION: Recurrent AF following selective PV isolation is overwhelmingly associated with PV electrical reconnection. Repeat PV isolation without linear ablation provides effective treatment for recurrent AF in patients in whom an initial PV isolation procedure failed, independent of clinical characteristics.     

Electrophysiologic and clinical consequences of linear catheter ablation to transect the anterior left atrium in patients with atrial fibrillation

OBJECTIVES: To evaluate the feasibility and outcome of ablation to transect the anterior left atrium (LA) in patients with atrial fibrillation (AF). BACKGROUND: While the Maze procedure is effective in maintaining sinus rhythm in patients with AF, it is associated with significant morbidity. This prospective clinical study evaluates the feasibility and consequences of limited LA linear ablation to transect the anterior LA in patients with AF. METHODS: Twenty-four patients (51.2 +/- 7.3 years) with paroxysmal (n = 16) or chronic (n = 8) AF resistant to pulmonary vein (PV) isolation were studied. To transect the anterior LA, linear ablation was performed joining the superior PVs; this line was then connected to the anterior mitral annulus. Pulmonary vein isolation and cavotricuspid isthmus ablation were performed in all cases. Ablation was performed using an irrigated catheter with the endpoint of achieving complete linear block demonstrated by online double potentials, differential pacing techniques, and an activation detour. RESULTS: Of 20 patients in AF prior to linear ablation, arrhythmia terminated in 12 (60%), including half the patients with chronic AF, during ablation. Despite repeated ablation, complete linear block was achieved in only 14 of 24 patients (58%). Complete linear conduction block resulted in an activation detour around the mitral annulus and PVs with a delay of 158 +/- 30 ms (P = .0001), significantly delayed activation of the lateral LA with prolongation of P-wave duration (P = .002), and characteristic change in P-wave morphology during sinus rhythm (P = .002). Of the 14 with anterior LA transection, 4 (29%) have had regular atrial tachycardias due to macroreentry through recovered gaps. Nine of these 14 (64%) have remained arrhythmia-free without antiarrhythmics compared to 3 of 10 (30%) with incomplete block at 28 +/- 4 months following their last procedure (P = .2). CONCLUSIONS: This study demonstrates the feasibility of catheter ablation to transect the anterior LA in humans. While being effective in the termination of AF, this configuration of linear lesions is technically challenging to complete, results in significant delayed LA activation, and is associated with modest long-term arrhythmia suppression.     

Incidence and time course of early recovery of pulmonary vein conduction after catheter ablation of atrial fibrillation

Background: Although it is well recognized that recovery of pulmonary vein (PV) conduction is common among patients who fail atrial fibrillation (AF) ablation, little is known about the precise time course of recurrence.
Objective: To determine the incidence and time course of early recurrence of conduction after PV isolation during AF ablation.
Methods: The patient population was composed of 14 consecutive patients (9 men [64%]; age 56 ± 7 years) with AF who underwent radiofrequency catheter ablation via circumferential ablation with PV isolation, determined by a circular mapping catheter. After successful isolation of the PVs, repeat circular electrode recordings from each PV were obtained at 30 and 60 minutes.
Results: After complete isolation of all PVs, early PV recurrence was observed in 13 (93%) patients and 26 veins (50%). Seventeen veins (33%) showed a first recurrence at 30 minutes, while nine veins (17%) showed a first recurrence at 60 minutes.
Conclusion: The results reveal an extremely high rate of early recurrence of PV conduction following AF ablation. It is particularly notable that about one-fifth of the veins remained isolated at 30 minutes, but subsequently developed recurrence between 30 and 60 minutes. Of the veins that showed early recurrence, one-third developed a first recurrence at 60 minutes. These findings suggest that AF ablation procedures should incorporate a 60-minute waiting period after initial isolation in order to detect early recurrence of conduction.     

Favorable effect of pulmonic vein isolation by partial circumferential ablation on ostial flow velocity

OBJECTIVES: The aim of this study was to determine the effect of electrical isolation of pulmonic vein (PV) on flow velocity. BACKGROUND: We report our experience with electrical isolation of PV by partial circumferential ablation and its effect on ostial peak flow velocity as assessed by phased-array ultrasound catheter imaging. METHODS: Sixty-two patients participated in the study. Magnetic electroanatomic mapping, ultrasound catheter imaging, and Lasso mapping catheter were used. Electrical isolation was achieved by delivering radiofrequency ablation (RFA) lesions proximal to Lasso mapping catheter bipoles showing PV entry. Following this, the number of RFA lesions/PV and their segment-wise distribution (maximum 4/PV) were assessed. RESULTS: Fifty right superior, 51 left superior, 32 left inferior, and 17 right inferior PVs were isolated. RFA involved 4 segments in 42 PVs, 3 segments in 61 PVs, and 90% reduction in AF burden, either with or without previously ineffective antiarrhythmic agents, was achieved in 54 patients (87%). CONCLUSIONS: In the majority of PVs (72%), electrical isolation can be achieved by partial circumferential ablation (targeting 相似文献   

Efficacy and safety of targeted focal ablation versus PV isolation assisted by magnetic electroanatomic mapping

INTRODUCTION: Pulmonary vein (PV) triggers initiate atrial fibrillation (AF). The aim of this study was to compare the outcome of focal PV ablation versus targeted PV electrical isolation aided by multipolar catheter recordings in the coronary sinus (CS) and right atrium and magnetic electroanatomic mapping (MEAM) for drug-refractory AF. METHODS AND RESULTS: Multipolar recordings identified PVs with triggers based on PV ostial pace map match for spontaneous and provoked triggers. PV triggers were provoked by isoproterenol, adenosine, and AF induction followed by cardioversion. MEAM defined PV ostial anatomy and assisted in localization of AF trigger and ablation lesions. All focal PV ablation procedures preceded PV isolation procedures at our institution. To limit a learning curve effect and validate the comparison, the results included outcome of procedures by a single experienced operator in the last 32 consecutive patients undergoing focal PV ablation and in 75 consecutive patients undergoing PV isolation. Patient characteristics were similar with respect to mean age (50 vs 52 years), mean left atrial size (4.3 vs 4.2 cm), presence of paroxysmal AF (84% vs 88%), and demonstration of non-PV triggers (16% in both groups). PV isolation was confirmed in 99% of PVs by multipolar circular catheter. MEAM confirmed noncircumferential ostial ablation in 69% of PVs. Patients undergoing PV isolation had less AF from PV triggers at the end of ablation (1% vs 16%, P < 0.01); had less AF at 2 months (17% vs 42%, P < 0.001); and had 1-year freedom from AF of 80% versus 45% (P < 0.001). Adverse events were low in both groups with no stroke or symptomatic PV stenosis. CONCLUSION: Using the described techniques, PV electrical isolation of PVs demonstrating spontaneous and/or provoked triggers is superior to focal PV ablation, with marked differences in outcome by 2 months. MEAM confirmed the noncircumferential nature of ostial ablation for effective isolation of most PVs and may play a role in the low risk and good outcome observed. The good outcome of targeted PV isolation as described suggests the need for a prospective comparison of targeted versus empiric PV isolation techniques.     

Intermediate term outcome after electrogram guided segmental ostial pulmonary vein isolation using an 8 mm tip catheter for paroxysmal atrial fibrillation

IntroductionPulmonary vein isolation (PVI) is the most widely used procedure for ablation in patients with paroxysmal atrial fibrillation (AF). Not withstanding recent advancements in this field, including sophisticated three-dimensional (3D) based imaging and advanced ablation catheters with contact force technology, many patients and healthcare systems in developing countries will not afford such an expensive therapeutic procedure. There are no data from India analyzing the efficacy of PVI for PAF using conventional mapping and ablation. In this article, we have summarized the intermediate term outcome following PVI in patients with PAF using electrogram-based mapping and a 8 mm tip ablation catheter.MethodA total of 42 consecutive patients who underwent PVI for symptomatic PAF not controlled with at least one antiarrhythmic drug were studied in a tertiary care institute from March 2011 to June 2018. Patients with rheumatic AF were excluded. The pulmonary vein (PV) anatomy was assessed by pulmonary angiography during the ablation procedure. Using conventional electrophysiologic mapping, a variable curve Lasso catheter placed in the PVs was used to guide the earliest site of breakthrough. The segmental ostial PVI was performed using a 8 mm tip radiofrequency (RF) ablation catheter. Elimination of all PV ostial potentials and complete entrance block into the PV were considered indicative of complete electrical isolation. Follow-up visits were scheduled at one, three, and six months after the procedure, and every six months thereafter. History, symptom review, clinical examination, and 12-lead ECG were performed at each follow-up.ResultsAt pre-discharge, 34 patients (81%) were in sinus rhythm, while eight patients (19%) continued to have atrial fibrillation. The age of the study population was 51.5 ± 11.7 yrs. The mean follow-up duration was 44 ± 21 months (range 6–84 months). The number of PVs isolated included one (five patients, 11.9%), two (20 patients, 47.6%), three (12 patients, 28.6%), and four (five patients, 11.9%). In 42 patients, a total of 101 PVs were isolated. The right superior PV (RSPV) was isolated in 37 patients, the left superior PV (LSPV) was isolated in 39 patients, the left inferior PV (LIPV) was isolated in 14 patients, and the right inferior PV (RIPV) was isolated in six patients. The procedure duration was 125 ± 29 min and the fluoroscopy time was 47 ± 13 min. The number of patients who remained in sinus rhythm at 1, 6, 12, and 24 months were 34 (81%), 32 (76%), 30 (71%), and 26 (62%), respectively. Two patients of these underwent repeat PVI, which was successful, and they had freedom from AF episodes. Complications were rare. One patient had a minor pericardial effusion, and one patient had transient sinus pauses, which were conservatively managed.ConclusionConventional RF ablation using PV potential-based mapping and ablation with 8 mm tip catheters is safe for patients with PAF. The intermediate term outcome is satisfactory and cost-effective in our setting with limited resources.     

Balloon catheter ablation to treat paroxysmal atrial fibrillation: What is the level of pulmonary venous isolation?

BACKGROUND: Unlike the initial balloon ablation catheters that were designed to deliver ablation lesions within the pulmonary veins (PVs), the current balloon prototypes are fashioned to deliver lesions at the PV ostia. OBJECTIVE: Using electroanatomical mapping, this study evaluates the actual location of ablation lesions generated by cryo-based, laser-based, or ultrasound-based balloon catheters. METHODS: In a total of 14 patients with paroxysmal atrial fibrillation, PV isolation was performed using either a cryoballoon catheter (8 patients), laser catheter (4 patients) or ultrasound balloon catheter (2 patients). Patients underwent preprocedural computed tomographic/magnetic resonance imaging. An intracardiac ultrasound catheter was used to aid in positioning the balloon catheter at the PV ostium/antrum. In all patients, sinus rhythm bipolar voltage amplitude maps (using either CARTO with computed tomographic/magnetic resonance image integration or NavX mapping) were generated at baseline and after electrical PV isolation as confirmed by use of a circular mapping catheter. RESULTS: Electrical isolation was achieved in 100% of the PVs. Electroanatomical mapping revealed that after ablation with any of the 3 balloon catheters, the extent of isolation included the tubular portions of each PV to the level of the PV ostia. However, the PV antral portions were left largely unablated with all 3 balloon technologies. CONCLUSION: Using the current generation of balloon ablation catheters, electrical isolation occurs at the level of the PV ostia, but the antral regions are largely unablated.     

Circumferential pulmonary vein isolation: the role of key target sites.

AIMS: Circumferential pulmonary vein isolation (CPVI) had been proved effective for treating atrial fibrillation (AF). However, the achievement of pulmonary vein (PV) isolation was sometimes challenging. PVs could not be isolated until some key target sites (KTSs) were ablated thoroughly. The aim of our study was to explore the distribution of KTSs. METHODS AND RESULTS: Four hundred and fifty-two cases (271 males, mean age 62.5 +/- 12.6 years) with drug-refractory AF were enrolled for catheter ablation. CARTO-guided CPVI was performed in all cases with one circular catheter for verification of PVs isolation. Target sites where PV potentials delayed, conduction sequence changed, slowed down, or isolated were defined as KTSs. From 452 CPVI procedures, 1520 KTSs were identified; 813 of which were located at left PV antrums and 707 were at right PV antrums. KTSs at left PV antrums were most commonly situated at anterior wall (63%), while KTSs at right PV antrums were most commonly situated at posterior wall (66.2%). Additional gaps ablation was performed for left PVs in 344 cases and for right PVs in 248 cases owing to incomplete PVs isolation by a single attempt of CPVI. One thousand one hundred and fifty-eight KTSs were identified, 662 of which were located at left PV antrums and 496 were at right PV antrums. At the anterior wall, 66.1% of left PV KTSs were located, and 67.9% of right PV KTSs were located at the posterior wall. Out of 1158, 961 (82.99%) KTSs were predicted correctly by circular mapping. PV isolation could not be achieved until some KTSs were ablated by higher power, longer duration, and higher irrigation rate than usual. CONCLUSION: KTSs during CPVI were most commonly situated at the anterior wall of left PVs and at the posterior wall of right PVs. Circular mapping within ipsilateral PVs' ostia could accurately predict the location of KTSs. Some KTSs must be ablated thoroughly by applying higher power, longer duration, and higher irrigation rate than usual to achieve PV isolation.